1. Field of the Invention
The present invention relates to a method for manufacturing a printed wiring board which includes a core substrate having a penetrating hole, a first conductor and a second conductor formed on the core substrate, and a through-hole conductor formed in the penetrating hole and connecting the first conductor and the second conductor.
2. Discussion of the Background
In Japanese Laid-Open Patent Publication 2006-41463, a penetrating hole is formed by forming a first opening portion from an upper-surface side (a first-surface side) of a core substrate using a laser, and by forming a second opening portion from a lower-surface side (a second-surface side) using a laser as well. The first opening portion tapers toward the second surface, and the second opening portion tapers toward the first surface. Then, by filling the inside of the penetrating hole with plating, a through-hole conductor with a small diameter is formed and the upper and lower surfaces of the core substrate are connected. The contents of this publication are incorporated herein by reference in its entirety.